Oxidative hair dye colorants are essential elements in hair dyeing preparations for the permanent dyeing of human hair. The hair dyeing process is achieved, in general, by the reaction of certain developing compounds with certain coupling compounds in the presence of a suitable oxidizing agent or compound, such as hydrogen peroxide.
When oxidation dye precursors such as those comprising primary intermediates and couplers are used in the dyeing of human hair, the procedure may involve the use of a two part system. In general, one part can be a formulation which contains a variety of ingredients, including oxidation dye precursors (i.e., primary intermediates and coupling agents). The other part is a developer formulation containing a suitable oxidizing agent, e.g., hydrogen peroxide. Immediately prior to application to the hair, the two parts are mixed to form a thickened liquid solution, for example, a lotion or a gel. As a consequence of the oxidizing properties of the oxidizing agent, some of the natural melanin pigment of the hair may be bleached. The dye precursors in the thickened solution (e.g., lotion or gel) penetrate into the hair and the primary intermediates are oxidized and react with coupling agents to produce the desired color. Such systems generally contain a proportion of organic solvents and surfactants and contain relatively high levels of dye precursors to produce the desired color.
In order for procedures using permanent oxidative dyes to work properly, a number of parameters and conditions are important to consider in the use of the permanent oxidative dye intermediates in admixture with couplers in hair color preparations for human hair. Among these are the final color and color intensity that are produced after application to the subject's hair; the wash fastness and the light fastness of the resulting dye; the resistance of the dye to perspiration; the resistance of the dye to various hair treatments, such as permanent wave, straightening, shampooing, conditioning and rubbing. In addition, the dye must have virtually no allergenicity or dermal or systemic toxicity.
p-Phenylenediamine (PPD) plays a very important role in oxidative hair coloring because a majority of shades are obtained with dyes based on this compound. The hair coloring industry is searching for a p-phenylenediamine alternative which possesses a better allergenic profile than p-phenylenediamine.
German Patent 377,288 (1923) discloses that coupling 4-amino-2,6-dichlorophenol with 2,4-diaminoanisole dyed hair blue black. German Patent 3,145,141 discloses oxidative dyeing compositions containing 4-amino-2,6-dichlorophenol, as the developer, and at least one of 1-naphthol, 1,5-dihydroxynaphthalene, m-aminophenol and N,N-bis(2-hydroxyethyl)-m-phenylenediamine, as the coupler. These compositions provide deep blue to black blue colorations which do not change when subjected to permanent waving treatments using thioglycolate or sulfite.
4-Amino-2-chlorophenol has been frequently mentioned as a part of extensive list of 4-aminophenol derivatives as a primary intermediate in patents on hair coloring. However, the usefulness of this compound has not been demonstrated in the prior art. Prior art references which mention 4-amino-2-chlorophenol include:
U.S. Pat. No. 5,540,738 which relates to single-stage oxidative hair coloring compositions containing iodide, oxidant and oxidative dye;
EP 605,320 A1 which discloses oxidative hair dye compositions containing paraphenylenediamines, metaphenylenediamines, and benzimidazole derivatives;
EP 465,340 A1 which teaches acidic oxidative hair dye containing 4-hydroxyindole;
EP 465,339 A1 which relates to acidic oxidative hair dye containing 4-hydroxyindole;
EP 459,900 A1 which discloses hair dye preparations containing 2,4-diamino-1,3-dimethoxybenzene as a coupling agent in acidic medium;
EP 446,132 A1 which teaches a process for dyeing keratinous fibers with 6- or 7-monohydroxyindoles at acidic pH; and
EP 410,471 A2 which relates to aminophenols, nitrophenol intermediates and their preparation, and hair-dyeing compositions containing as couplers.
1-Phenyl-2-pyrazolin-5-one has also been mentioned in prior art patents.
GB 2,168,727 A describes a dyeing composition for keratinous fibers, and especially for human hair. The composition contains at least one oxidation dye precursor and at least one water-soluble bio-heteropolysaccharide and an oxidizing agent. 3-Methyl-1-phenyl-2-pyrazolin-5-one is mentioned among many couplers.
U.S. Pat. No. 4,212,645 covers hair dyeing compositions containing an aryldiamine and a substituted catechol. Substituted catechol derivatives together with p-phenylediamine derivatives can be employed to impart permanent dark or intense colors to the hair in the absence of a peroxide or metal peroxide. Color is generated in the presence of atmospheric oxygen. 3-Methyl-1-phenyl-2-pyrazolin-5-one is mentioned as one of the couplers to vary the shade of the hair.
U.S. Pat. No. 4,169,703 covers a composition useful for dyeing keratinous fiber red without using o-, m-, p-phenylenediamine, 2,4-diaminoanisole or nitro compounds. In this patent, 3-methyl-1-phenyl-2-pyrazolin-5-one is described as an antioxidant.
U.S. Pat. No. 4,003,699 describes oxidation hair dyes based upon tetraaminopyrimidine developers. 1-Phenyl-2-pyrazolin-5-one derivatives, including 3-methyl-1-phenyl-2-pyrazolin-5-one and 3-amino-1-phenyl-2-pyrazolin-5-one, have been disclosed as couplers. With tetraaminopyrimidine, they produce a wide range of colors ranging from brownish orange to red, brick red, tomato red and reddish brown.
DE 2,357,215 covers 2,3,4,6-tetraaminopyridine as a primary intermediate. It couples with 3-methyl-1-phenyl-2-pyrazolin-5-one and 3-amino-1-phenyl-2-pyrazolin-5-one to produce red brown and bloody red respectively.
3-Acetamino-1-phenyl-5-acetoxy-1H-pyrazole was reported in Bull. Soc. Chim. Fr. (1974, pages 291-293). However, its use as a hair dye was not appreciated by those skilled in the art.